After a plurality of semiconductor chips have been packaged into a device, any voltages applied to the packaged device, including any test voltages, are limited by the normal operation voltage ranges of the device controller that resides inside the packaged device. However, in order to perform semiconductor chip characterization, such as stress tests, a voltage that is higher than the normal operation voltage ranges of the device controller is needed. However, applying such higher test voltages may damage the device or device controller.
Thus, the danger for damage to a device, once packaged, places undue limits on testing. And, if limits of a packaged device are not fully tested, failures may not be discovered until products embodying such devices fail for customers.
It is within this context that the present invention arises.